Researchers at the University of Chicago have trained an artificial intelligence system, to write fake reviews on Yelp, a website showing customers reviews on shopping or something else, and it's pretty hard to tell them apart from a human review. Their study, which will be presented at the ACM Conference on Computer and Communications Security in October, aimed to throw attention onto how easily these systems can write reviews like humans and how damaging they can become if they’re not monitored properly. Since many small businesses rely on online reviews to help grow and keep their reputation, a future where someone—like a rival or angry customer—could crazily fill their page with negative reviews written by a machine is pretty worrying. And, according to the research team, the threat goes far beyond a bunch of fake reviews on Yelp. “In general the threat is bigger,” Ben Y. Zhao. one of the authors of the study, said. “I think the threat towards society is large and it really misleads users and shakes our belief in what is real and what is not. I think that' s going to be even unimaginable.” To test how believable these reviews came across, the researchers invited 40 volunteers and had AI generate five fake reviews for 40 actual restaurants. The volunteers were asked how useful they thought the review was and whether or not they thought it was fake. The AI reviews ranked as “effectively indistinguishable” from real reviews,according to the study. Further, the fake reviews were given a 3.15 "usefulness" rating, compared to a 3.28 rating for human reviews.